WHO HID IT?

One of the first two (1977) books, never before published here, of a Japanese illustrator noted for his bold simplicity and striking designs, this seven-inch square book not only challenges children to find objects cleverly concealed in the pictures but is also a counting book. ``Who hid the candles?'' They serve as horns on one of five giraffes; ``Who hid the fork and spoon?'' They dangle from the pigtails of one of 12 children. In the same format, the second book, Who Ate It?, is equally attractive, but ``ate'' is not the mot juste: the different foods are hidden on the outsides of the animals. A fine, economical purchase for the youngest. (Picture book. 0-6